1. Field of the Invention
The present invention relates to a focused lighting device, and in particular, to a focused lighting device which uses partitions or light guides disposed on its hood body to significantly reduce or homogenize light beams other than main light beams.
2. Description of the Related Art
With today's improving technology, people's lives are becoming more convenient and comfortable everyday, and lighting is indispensable to our daily lives. Conventional bulbs use filaments to generate light; for example, filament made of tungsten wires is connected to a circuit to become a point light source and emits light from the center. This type of bulb consumes significant energy and generates a large amount of heat, as well as having a short service life. To overcome these drawbacks, light emitted diodes (LEDs) have been developed for use as light sources.
The LEDs that are available in the market are usually made by placing LED chips on the center of a base and then packaging by epoxy resin or silicone externally. The top of the packaging is slightly curved to act as a convex lens, which enables the light generated from the chip to be refracted with a predetermined projection angle.
LEDs are characterized by low power consumption and long service life. However, when the intensity of a single LED light source is increased, the light-emitting area increases as a result, so that the existing optical focusing system cannot project the main light beam at a small angle. For this reason, if a plurality of LEDs is used for projection, a single optical system cannot be used to project the light beams emitted from a plurality of LEDs into a small-angle main light beam.
Consequently, to meet such a need, a Republic of China patent (ROC Pat. No. 5495570) and a United States patent (U.S. Pat. No. 7,011,432) disclose a device in which a plurality of LEDs are correspondingly arranged on a reflective hood having a plurality of reflective mirrors, and the light beams emitted from the LEDs are projected outwardly through the reflective mirrors of the reflective hood. This design simulates a plurality of light sources as a center light source to project light outwardly, so as to overcome the difficulty in enhancing the projection intensity of the LEDs. However, the center light source formed by simulating a plurality of LEDs cannot project all the emitted light to the corresponding reflective mirrors; rather, some light beams will be projected on to other reflective mirrors in addition to their corresponding reflective mirrors, thereby forming a secondary stray-light ring around the main light beam, which degrades the lighting quality and affects the application of the simulated center light source on the lighting devices.